7. CONCLUSIONS

In theoretical cosmology Cosmic Inflation sits at the interface between
the known and unknown. The end of inflation is designed to connect
up with the Standard Big Bang model (SBB) which is highly successful at
describing the current observations. Before inflation lies a
poorly understood chaotic world where apparently anything goes, and
even the laws of physics are not well understood.

Given that inflation is straddling these two worlds, it is not
surprising that many open questions exist. Despite these open
questions, inflation does a strikingly good job at addressing
simpler questions that once seemed deep and mysterious when all we had
was the SBB to work with. In particular, inflation teaches how
it is indeed possible for nature to set up the seemingly highly
``unnatural'' initial conditions that are required for the
SBB. Furthermore, inflation gives us a set of predictive signatures which lie
within scope of realistic tests.

Already the confrontation with current observations is strongly
favoring inflation. Upcoming large-scale surveys of the Universe
promise that the pace of these confrontations will pick up over the
next several years. Thus we should know in the foreseeable future
whether we should continue to embrace inflation and build upon its
successes or return to the drawing boards for another try.

Acknowledgments

I wish to thank Alex Lewin for comments on this manuscript, and
acknowledge support from DOE grant DE-FG03-91ER40674, and UC
Davis. Special thanks to the Isaac Newton Institute and the organizers
for their hospitality during the this workshop.